A detailed water consumption analysis
Methodology & assumptions
The estimates below are built from industry benchmarks for 4-star hospitality operations, adjusted for Hugarro’s strong water-conservation focus (low-flow showerheads, dual-flush toilets, modern laundry machines and unique closed-circulation geothermal pool heating system.
Two scenarios are presented:
- Low scenario — minimum occupancy (≈60%), best-in-class water efficiency
- High scenario — near-full occupancy (≈95%), standard conservative usage
Occupancy & headcount assumptions
| Facility | Capacity | Low Scenario | High Scenario |
|---|---|---|---|
| Hotel rooms (32) | 200 guests | 120 guests (22 rooms) | 190 guests (30 rooms) |
| Cabins bath+shower (20, max 2 pax) | 40 guests | 24 guests | 40 guests |
| Cabins shower only (12, max 4 pax) | 48 guests | 32 guests | 48 guests |
| Staff cabins (10, max 2 pax) | 20 staff | 10 staff | 20 staff |
| Meeting cabins (5) | ~50 day visitors | 10 persons | 40 persons |
| Hot springs visitors | 400/day | 200/day | 400/day |
| Hot springs restaurant (50 seats) | ~150 covers/day | 50 covers | 150 covers |
| Hotel restaurant + bar | ~300 covers/day | 200 covers | 300 covers |
🚿 Potable water consumption
Used for: human consumption, showering, bathing, inside cleaning, laundry
Unit benchmarks applied:
- Shower (low-flow, 6–10 L/min): mandatory hot springs shower 1.5 min = 9–15 L/person 2
- 4-star hotel room benchmark: 140–300 L/guest/night (potable items minus toilet) 68
- Modern laundry: 5–10 L/kg linen; assume 3–5 kg/room/day 5
- Restaurant/kitchen: 30–60 L per cover (kitchen, dishwashing, staff) 3
| User Area | Detail | Low (m³/day) | High (m³/day) |
|---|---|---|---|
| Hotel rooms | 120–190 guests × 120–200 L/guest (shower, sink, drinking; excl. toilet) | 14.4 | 38.0 |
| Cabins bath+shower (20) | 24–40 guests × 130–220 L (incl. bath fill 150–200 L) | 3.1 | 8.8 |
| Cabins shower only (12) | 32–48 guests × 100–160 L/guest | 3.2 | 7.7 |
| Staff cabins (10) | 10–20 persons × 100–150 L/person | 1.0 | 3.0 |
| Hotel restaurant + bar | 200–300 covers × 30–60 L/cover (kitchen, dishwash, bar) | 6.0 | 18.0 |
| Hot springs restaurant | 50–150 covers × 30–60 L/cover | 1.5 | 9.0 |
| Hot springs showers | 200–400 visitors × 2 showers × 1.5 min × 6–10 L/min | 3.6 | 12.0 |
| Inside cleaning / housekeeping | Hotel + cabins rooms/surfaces; ~10–20 L/room occupied | 0.5 | 2.0 |
| Meeting cabins | Drinking water only; 10–40 persons × 2–5 L | 0.02 | 0.2 |
| In-house laundry | Hotel + cabins linen 3–5 kg/room × 6–10 L/kg; hot springs towels 200–400 sets × 0.5 kg × 6–10 L | 1.4 | 5.1 |
| POTABLE SUBTOTAL | ~34.7 | ~103.8 |
🪣 Filtered (non-potable) water consumption
Used for: toilet flushing, outdoor cleaning, gardening, car washing, fire system, pool suppletion
Unit benchmarks applied:
- Dual-flush toilet (water-saving): avg 4–5 L/flush, ~4 flushes/person/day 4
- High-pressure car wash: 30–80 L/vehicle 7
- Pool suppletion: given max 25 m³/day (covers evaporation + UF process losses)
| User Area | Detail | Low (m³/day) | High (m³/day) |
|---|---|---|---|
| Toilet flushing — hotel, cabins, staff, meeting | ~200–350 persons × 4 flushes × 4.5 L/flush | 3.6 | 6.3 |
| Toilet flushing — hot springs facility | 200–400 visitors × 2 flushes × 4.5 L | 1.8 | 3.6 |
| Outdoor/facility cleaning | Hard surfaces, equipment, pathways | 0.2 | 1.0 |
| Gardening / irrigation | Iceland climate (moderate, partial landscaping) | 0.5 | 3.0 |
| Car washing (high-pressure) | 20–60 vehicles/day × 30–80 L/vehicle | 0.6 | 4.8 |
| Fire hydrant system | Standby / periodic testing (not an active daily draw) | 0.05 | 0.1 |
| Geothermal pool suppletion | Evaporation + UF process water losses (given: max 25 m³/day) | 10.0 | 25.0 |
| FILTERED SUBTOTAL | ~16.8 | ~43.8 |
♨️ Geothermal water
| Use | Consumption | Notes |
|---|---|---|
| Heat extraction (heat exchangers) | Net zero consumption | Water is circulated through heat exchangers and fully returned to the aquifer. Zero net extraction. Long-term sustainability protected. |
🚽 Sewage / Wastewater
| Stage | Volume (estimated) | Notes |
|---|---|---|
| Raw sewage generated | Low: ~40 m³/day | High: ~120 m³/day | Approximately 80–90% of potable + some filtered water input |
| After 2-stage treatment | Low: ~36 m³/day | High: ~108 m³/day | Quality suitable for irrigation/car wash reuse |
| Current disposition | Filtered into soil | Could offset significant filtered water needs in future |
🔬 UF Plant — potable water treatment losses
When filtered water is upgraded to potable, the UF treatment plant itself consumes water for backwashing. At typical UF recovery rates of 90–95%: 1
| Scenario | Potable demand | Feed water needed | UF process waste |
|---|---|---|---|
| Low | 34.7 m³/day | ~37.7 m³/day | ~3.0 m³/day |
| High | 103.8 m³/day | ~113.0 m³/day | ~9.2 m³/day |
This UF waste becomes part of the sewage/drainage stream.
📊 Consolidated Summary
| Water Type | Low (m³/day) | High (m³/day) |
|---|---|---|
| Filtered — all other uses (toilets, garden, cars, etc.) | 6.8 | 18.8 |
| Filtered — pool suppletion (evaporation) | 10.0 | 25.0 |
| Filtered — UF pool plant process waste | 3.0 | 9.2 |
| Filtered subtotal (revised) | ~19.8 | ~53.0 |
| Potable water consumed | 34.7 | 103.8 |
| TOTAL gross water extraction | ~58 | ~165 |
⚖️ Comparison with extraction permits
| Source | Permit | Hourly | Daily Capacity |
|---|---|---|---|
| Drilled well | 11 m³/hr | 264 m³/day | |
| Mígandalaekur creek | 5 m³/hr | 120 m³/day | |
| Total permitted | 384 m³/day |
| Scenario | Total extraction needed | % of permit used | Surplus |
|---|---|---|---|
| Low | ~58 m³/day | 15% | 326 m³/day |
| High | ~164 m³/day | 43% | 220 m³/day |
Winter source capacity
| Source | Summer (permitted) | Winter (actual) |
|---|---|---|
| Drilled well | 264 m³/day (11 m³/hr) | 264 m³/day (unchanged) |
| Mígandalaekur creek | 120 m³/day (5 m³/hr) | 43.2 m³/day (0.5 L/s) |
| Total available | 384 m³/day | 307.2 m³/day |
The creek drops from a generous 120 m³/day to just 43.2 m³/day in winter — a loss of 76.8 m³/day. However, the well alone at 264 m³/day more than covers all operational needs.
Winter capacity vs. consumption
| Scenario | Consumption | Winter Capacity | Surplus | % Used |
|---|---|---|---|---|
| Low | 58 m³/day | 307.2 m³/day | 249.2 m³/day | 19% |
| High | 165 m³/day | 307.2 m³/day | 142.2 m³/day | 54% |
Key observation
The well alone (264 m³/day) already exceeds even our worst-case daily consumption (165 m³/day) by 99 m³/day. The creek in winter is essentially a bonus source, not a critical dependency.
One practical note worth flagging: in cold Icelandic winters, creek flow can be further affected by freezing. This accounts for ice-reduced flo. Even in that extreme case, the well alone keeps us fully operational.
✅ Both scenarios are well within permitted limits, confirming ample capacity to supply neighbouring communities and local businesses with treated drinking water, as planned.
Additional notes & caveats
- Geothermal pool UF waste is already factored into the 25 m³/day pool suppletion figure (as stated), so it is not double-counted.
- Sewage water reuse — if the treated sewage (2-stage) is eventually used for irrigation and car washing, this could offset 3–8 m³/day of filtered water demand.
- Iceland climate moderates outdoor irrigation needs significantly vs. southern European resorts.
- Hot springs showers are short (1.5 min mandatory) but high-volume due to 400 visitors. Even with low-flow heads at 6–8 L/min, this is a meaningful potable water draw (3.6–12 m³/day).
- Bathtub cabins carry disproportionate water intensity — a single bath fill of 150–200 L versus ~45 L for a 6-minute shower. Offering incentives to use showers over baths would meaningfully reduce consumption.
- Laundry represents only 1.4–5.1 m³/day with modern machines — a significant improvement over older equipment (which could reach 15 L/kg).
- The hotel restaurant is the single largest potable water consumer after hotel rooms, due to kitchen and dishwashing operations at scale.